For 2012, Power-Efficient Servers Could Get a Shot in the ARM

In 2012 a fundamental change in server architecture could be on tap as companies look to cut data center costs with the help of technologies like ARM processors and graphics chips, analysts said.

Low-power processors from companies like ARM could be in full use in data centers by 2013, and mixing them up with graphics chips could bring massive performance improvements and power savings, analysts said. Experiments around implementing ARM processors in servers are already underway, and graphics chips are already being used in some of the world's fastest supercomputers.

Power efficiency has been among the top determining factors in server purchases as customers keep costs in mind while deploying applications, analysts said. This year, there was a spike in the build-out of cloud and high-performance servers around the hyperscale model, in which servers are densely packed to cut power consumption while scaling performance. For further power savings, companies in the future could consider using servers with low-power ARM processors, which are used in most tablets and smartphones today.

"Customers are experimenting with a lot of different technologies. They are trying to gain efficiency," said Jed Scaramella, research manager at IDC. Companies are measuring dollars-per-kilowatt and dollars-per-square-foot, and in servers measuring performance-per-watt more closely than ever.

The growth of the cloud is partly driving server sales, with many companies building out public and private clouds. Many two-socket x86 servers were purchased for cloud implementations around the hyperscale model, which allows new servers to be easily plugged in to scale performance. Servers in the hyperscale model are also being used for applications such as analytics and business intelligence.

"They're not disposable, but they are aimed at a low-cost point. It's really about energy efficiency ... and how fast you can scale them," Scaramella said.

Dense servers with ARM processors could be an alternative to x86-based technology in the coming years as IT managers factor in density and lower-power requirements. Analysts have said that a congregation of low-power ARM processors could provide more power-efficient processing of cloud transactions than traditional x86 server chips like Intel's Xeon or Advanced Micro Devices' Opteron, which are more power hungry. The chips based on ARM processors would however lag x86 chips on data-intensive tasks such as database and ERP (enterprise resource planning).

Some companies this year introduced experimental servers with ARM processors. Hewlett-Packard last month announced server designs with a chip from Calxeda, which includes a quad-core ARM processor and consumes as little as 1.5 watts of power. Nvidia last month said a supercomputer was being built in Barcelona around its Tegra 3 chip, which has a quad-core ARM CPU, and that the Tegra 3 chips were being paired with discrete graphics processors to speed up scientific and math calculations.

"What happened this year is you started to see the roadmaps and products. It became 'real' but that doesn't mean it's going to gain market share next year," Scaramella said.

A break in traditional server architecture with ARM will be closely watched, but the impact will be felt in 2013 at the earliest, said Dan Olds, principal analyst at Gabriel Consulting Group. Almost every major server maker could be experimenting with ARM processors, Olds said.

"If it's real enough for an HP to give it a shot, that means it's real," Olds said. "It depends upon what you think about the 64-bit roadmap for ARM."

Current ARM processors only support 32-bit addressing and also have limited error correction features. With 64-bit, computers can address larger amounts of storage and memory, which is beneficial for data-intensive applications. ARM in late October introduced its first 64-bit microprocessor architecture, ARMv8, aiming it at devices ranging from sensors to high-end servers.

The idea of coupling graphics processors with ARM processors is also fascinating, Olds said. Graphics processors are being used on many of the world's fastest supercomputers, and are capable of much faster performance at running some applications than traditional CPUs.

"Such a combination would offer much higher density, more computations per watt and lower cost," Olds said.

Graphics processors are trickling down from high-performance computers and are being used increasingly used for high-performance computing in the energy, pharmaceuticals, financial services, media and other industries, Olds said.

But analysts agree that switching from x86 to ARM could be a challenge due to the hardware and software issues. Customers are already struggling with decisions on purchases with many server options available, including workload-optimized systems that bundle the server, storage, networking and software. Switching to ARM could be disruptive and have its benefits, but it may take time to implement.

Purdue University CIO Gerry McCartney echoed that belief, saying the university has a lot invested in its current IT infrastructure. The university largely relies on x86 servers, and a lot of the code used by researchers is written for the x86 instruction set.

"Researchers do not want to change software," McCartney said. He said an effort many years ago to move from x86 to another architecture didn't pan out, and a lot of thought would go into switching over to a new architecture.

But the university likely won't move away from x86 because Intel's server chips are becoming increasingly power-efficient, McCartney said. As an example, Purdue's Carter supercomputer, which ranks 54th on the world's Top 500 list of the world's fastest supercomputers, provides more performance-per-watt than four supercomputers with Intel chips bought over the last four years.

"I could get rid of the four previous machines, and use a quarter of the power that they are currently now consuming," McCartney said. The performance-power ratio on Intel chips is improving with every new chipset, he said.

"There have been some modest improvements in space, and we're pleased in terms of power consumption," McCartney said.